District 5 Diary

Rob Anderson's commentary on San Francisco politics from District 5

Monday, March 09, 2009

State of Cycling Report: The fix was in

Steve Jones called me recently to get the so-called anti-bike perspective on the Draft EIR on the Bicycle Plan. During our conversation he insisted that 6% of all trips in the city are by bicycle, a number I was skeptical of. He claimed that he got that number from the MTA, but I couldn't find it in the reports the agency has posted on its website. Instead it seems to be from the "State of Cycling Report" of September, 2008, which isn't posted on the MTA's website[Later: it is now], probably because the methodology used by the folks at Berkeley's Alta Planning to prepare the report was seriously flawed: 400 of the interviews were conducted at "energizer stations" on Bike to Work Day. Alta was so uncomfortable with that approach---insisted on by the city, evidently---that it even mentions the issue in the report:

The team conducted intercept surveys on Bike to Work Day as it was an extremely efficient method of collecting the desired number of cyclist responses...However, this sampling method over-represents people who bicycle to work. In the future, if finances allow, the City should consider conducting intercept surveys separate from Bike to Work Day (page 31).

Yes, it's an understatement to say that interviewing cyclists at energizer stations on Bike to Work Day "over-represents" the number of people in the city who bike to work. It would even be fair to say that using that methodology is guaranteed to exaggerate the number of cyclists in the city, in effect rigging the results of the report before it's even written.